Slab on grade (Moment)
Slab on grade (Moment)
(OP)
I need to know if there is a book/reference on how to design slab on grade subjected to concentrated moment and tention. common case if a jib crane is installed in already buit factory. any idea how to chack if its ok or not?






RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
RE: Slab on grade (Moment)
There is unfortunately little to it. I did come upon a book 'Ground Bearing Concrete Slabs' by John Knapton.
He goes through several methods; none of which I particularily liked. Based on loading his methods alter the depth of the slab; with pretty much the same steel remaining on all condition, standard 8 or 10mm structural mesh. It is worth a read though as I havent explained it very well.
I specced some minor top steel to control cracking and hopefully resist hogging moments at the corners and edges of the slab.
It is difficult when you're analysing the slab to take a point load, such as a fixed crane or a mobile crane outrigger, and determine where the load is spread out to. As if the slab is very stiff it could be spread far out from where the load is applied.
In the end I took my point load as acting on a 'pad' of the slab two square metres. Checked for bending and punching, was ok - so I moved on. Its not a correct method but it will give you an indication of whether your slab is adequate.
I would echo the original posters question; if you have a point load coming onto a ground bearing slab on grade; how do you determine the area that this load bears onto; how do you define its extents?
RE: Slab on grade (Moment)
There is a good example of flexible foundation in the foundation book by B.M DAS.
RE: Slab on grade (Moment)